The social and economic impact of degenerative diseases affecting bone tissue makes it necessary to develop synthetic bone substitutes that are capable of exhibiting superior biofunctional properties, above all in orthopaedics, where surgical operations for bone reconstruction and regeneration are steadily increasing and increasingly involve young patients who are still active. In this regard, the biomechanical properties required of a bone substitute are particularly important, in order for it to promote the development and remodelling of new bone tissue under mechanical loads, minimizing recourse to fixation techniques, while at the same time being integrated and resorbed as much as possible by the newly forming bone tissue.
The remarkable and unsurpassable biomechanical properties of natural bone are strictly a consequence of its anisotropic morphology that is hierarchically organized in a range of scales from sub-micrometer to the macroscopic dimensions, so that the bone tissue is able to adapt continually to changes in the mechanical load. On the basis of these continual and varying stresses, the bone remodels itself by means of mechanisms in the cells that act as sensors of variations in the pressure of the extracellular fluid due to mechanical stimuli. Such mechanisms permit the removal of damaged bone and its substitution with new tissue having an organized, and thus fully functional morphology. This mechanism is of crucial importance for the survival of bone tissue subjected to mechanical loads and it can be activated only in the presence of a hierarchically organized structure.
As yet, an optimal solution for the replacement and regeneration of portions of bone subjected to mechanical loads (load-bearing) has not been found, as there are no known bone scaffolds that are both bioactive/bioresorbable and resistant to the mechanical loads to which certain bone portions of the body are subjected, such as the long bones of the leg or arm (for example the metatarsus, femur, tibia, humerus and radius).
This drawback is overcome by the present invention, which makes available a bone substitute for bone generation in general and in particular for the regeneration of portions of bone preferably subjected to mechanical loads (load-bearing) as outlined in the appended claims.